2. Calcium stearate disperses evenly in coated sand, and the resin and calcium stearate soften and melt at core temperature. The lubricity of calcium stearate can improve the fluidity of coated sand, increase the compactness of sand core and increase the strength of coated sand core.

3. The melting point of calcium stearate is higher than resin. Calcium stearate is beneficial to improve the thermoplasticity of sand core, which relaxes the thermal stress of sand core. Although the amount of calcium stearate in coated sand is very small, it can prevent the clotting, improve the fluidity, and improve the resistance to shell and molds.